Worldwide wireless voice and data access has recently become more prevalent. Wireless devices may be carried to many countries, almost anywhere in the world, and provide both voice and data access for a user. When a user roams outside of the area of his home network, he is said to be “roaming”. Many prior art systems allow for such roaming by permitting the user to connect to a network in the area where he is roaming.
For explanation purposes, we define herein a visited network as the network, other than the home network to which a wireless device user is a subscriber, to which a user has access. We also refer herein to the home network as the wireless network of which the wireless device is a subscriber. Thus, for example, if a user is normally a registered subscriber in New Jersey, but travels to Toronto, Canada, a local wireless network operator in Toronto Canada to which the user has access, but to which the user is not a registered normal subscriber, would be deemed a visited network. The term visited network therefore, is with reference to a particular wireless device in that a network may be a visited network for one wireless device but may be the home network for another wireless device.
In order to provide the aforementioned roaming services, the various visited wireless networks must be capable of working with the home network. More particularly, if a user is a subscriber to home network in New Jersey, and travels to the United Kingdom, the visited network in the United Kingdom must have some way of coordinating with the home network back in the United States to insure proper authentication, billing, call routing, etc.
One manner in which this is typically accomplished is that the user's wireless device is detected by a visited network in the United Kingdom first. The United Kingdom visited network detecting the wireless device detects enough information to ascertain the identity of the home network associated with the wireless device. The visited network then contacts a home location register (HLR), maintained by the home network. For purposes of explanation, we assume herein that the HLR is a part of the home network, although it may be physically separate.
Usually, one of the first messages sent from the visited network to the home network has a well known standardized format, and is known in the art as a Location Update (LU) message. The HLR is a data base maintained by the home network that includes all of the necessary information and authentication data associated with a particular user. This information can then be transmitted back to the visited network, usually to a specific mobile switch within that visited network. In this manner, the home network can reject or authorize use of a visited network. One of the key messages transmitted from the HLR, to the visited network, in response to the LU, is called the Insert Subscriber Data message, or simply, the ISD. Generally however, there is a request from the visited network and a responsive message from the home network that either authorizes or refuses the request by the wireless device to use the visited network.
Additionally, the foregoing provides a manner in which the visited network can then bill the home network for the appropriate amount of air time and service. In this manner, a user of any network can use another network in some remote location, and this visited network will coordinate with the user's home network to facilitate billing, authentication, and other similar issues.
A slight complication to the above occurs when there are plural accessible visited networks at the user's location. Specifically, consider the situation of which a subscriber from New Jersey is roaming in Great Britain, and there are three networks that are accessible from the user's location. An issue arises as to which of the three networks should accept the user, interface with the user's home network back in New Jersey, and process the call or data access from the user's wireless device. Typically, contention among three such visited networks has been resolved by the handset picking the network with maximum signal strength, and/or applying a randomization factor when signal strengths are useable. Other factors may be utilized as well, such as a list of preferred networks which could be resident on the device's Subscriber Identity Module (SIM) card. This situation, however, means that the home network, with which the subscriber and wireless device are associated, has limited or no control over which visited network handles the call/data transmission.
A more sophisticated prior art system uses something called Steering of Roaming (SOR). An SOR system is depicted in relevant part in FIG. 1. SOR systems are intended to permit the home network to either determine or at least influence the particular choice of visited network to be used when plural such visited networks are available.
The prior art SOR platform 102 of FIG. 1 is operatively coupled to a home location register (HLR) 101, implemented on a computer with software and run by the home network. The various visitor location registers (VLR) are associated with the variety of the visited networks to which a traveling user may come within range.
In operation, when a user comes within range of a particular visited network, a VLR 106 associated with that visited network must first request authentication and other relevant information from the HLR 101. A message requesting same is sent from the particular VLR 106 through one of International Gateway Providers (IGP) 103-105 to HLR 101. One of these initial messages is most termed a location update (LU) message.
The SOR platform 102 determines if the requesting VLR 106 is associated with the particular visited network that the home network desires a roaming subscriber use. If not, the SOR platform 102 will intercept the request message and simply send back a rejection, leading the particular visited network to believe that the subscriber is either not authorized, or for some other reason is not permitted use of the visited network. In this manner, the wireless device will try other available visited networks, until a visited network is accepted by the SOR platform. Normally, within one or two tries, the visited network to which the home network desires to steer the call will be accessed, and the call will then be passed through the SOR 102 to the HLR for approval.
Several problems exist with the prior art approach of FIG. 1. First, the home network HLR 101 must maintain its own associated SOR platform 102. The SOR platform 102 is relatively expensive, and the home network operator would thus prefer, in certain circumstances, that the IGP providers 103-105 offer the service provided by the SOR platform 102. However, if an IGP includes a particular SOR platform, many messages will not be subjected to the SOR feature. This is because the various visited networks, and their associated VLR's 106, may utilize a different IGP to communicate with the HLR. Neither the home network, nor the HLR 101, has any real control over communications path utilized by a visited network to communicate the LU message.
Thus, for example, if IGP 103 includes an SOR feature 201, then VLR's that communicate with HLR 101 through the other IGPs 104 to 105 will not be subjected to the SOR feature. This is displayed in FIG. 2. As a result, it means that either all IGP's must have their own SOR platform, or the system will not work properly much of the time. This is because, in the arrangement shown in FIG. 2, the SOR functionality will only be applied to messages arriving via IGP 103, but not to messages arriving through the other IGPs. And, even if all IGPs have their own SOR, the coordination among all of them for the system to work properly would be cumbersome.
In view of the foregoing, there exists a need in the art for a more efficient manner in which to provide steering of roaming services.
There also exists a need in the art to provide steering of roaming services from an International Gateway Provider, so that the home network operator of the HLR does not have to invest in the costly hardware and software required for such services.